It is preferred that portable lifts be narrow enough to be moved through doorways. However, when the lifts are used at the job sites they frequently require lateral stabilization with ground engagement "foot prints" which are further apart than normal door width. Hence, laterally extending stabilizers have been employed which can be moved into an inactive storage position on the lift which effectively narrows the lift to less than door width. Some of the stabilizers used in the past have swung down from an upright storage position to an active ground-engaging position. Some of these swing-down stabilizers have had folding struts hinged at the center similar to common card table braces to hold the stabilizers in active position, and others have had ratcheting mechanisms limited to ratchet teeth positions for adjustment. A need has arisen for an improved locking system for swing-down stabilizers which automatically locks the stabilizer in both lowered and raised positions, is easy and safe to operate, and is of economical and sturdy construction.